You should apply Thompson's Water Seal every 1 to 3 years, depending on your local climate, sun exposure, and foot traffic. Horizontal surfaces (like decks) usually require reapplication every 1 to 2 years, while vertical surfaces (like fences) can last up to 2 to 4 years.
Because of this, you need to make sure that the surface is completely dry and free of debris prior to applying. If over-application occurs and there is puddling of the product, redistribute product within 15 minutes to a dry area or wipe off.
Thompson’s Water Seal typically lasts 1 to 3 years on exterior wood surfaces before it needs to be reapplied. However, the exact lifespan varies based on the product tier and environmental conditions, often requiring maintenance every 1 to 2 years in heavy-traffic or high-sun areas.
No, Thompson's Water Seal does not require two coats. In most cases, a single liberal coat is sufficient to provide excellent weather and water protection.
Water seal protects wood from water and sun damage. It acts like a barrier, keeping moisture out. Without a water seal, outdoor wood can fade, warp, or rot, and all other sorts of things can occur to your deck unfortunately. Thompson's Water Seal goes further.
Thompson Water Seal dries to the touch in 2 hours, but requires 24 to 48 hours to fully cure for foot traffic or before it can be exposed to rain.
That said, it should never be used in marine applications, countertops, or woodworking projects that come into direct contact with food, like bowls or cutting boards.
The best way to apply Thompson’s Water Seal is by using a paint pad applicator or a garden pump-up sprayer to ensure deep penetration. Thoroughly prep the surface, apply one single, thin, and even coat, avoid over-application, and let it cure for 24 hours without rain.
The best time to seal a deck is in late spring (May–June) or early fall (September–October) when temperatures are consistently between 50∘F and 90∘F and there is no rain in the forecast for 48 hours. Mild weather allows the sealer to dry evenly without bubbling or cracking.
Best Oil-Based
A 5-gallon pail of Ready Seal exterior wood stain and sealer covers approximately 625 to 750 square feet, depending on the porosity and texture of your wood.
If it rains after you seal a deck, the damage depends on how long the sealer had to cure. Rain within 2-4 hours will likely wash away or ruin the finish, causing peeling, blotchiness, or a milky film. If it rains after 12-24 hours, the sealer is usually safe.
Generally, no, you cannot paint directly over Thompson’s Water Seal. Because the sealer is designed to repel water using silicone, wax, or paraffin, fresh paint will not be able to adhere to the surface and will eventually peel, bubble, or flake off.
Thompson's Water Seal coverage typically ranges from 150 to 400 square feet per gallon. However, actual coverage varies widely depending on the texture and porosity of the material you are sealing.
Removing Waterproofers and Stains
Apply and in minutes you can scrub and rinse away old finishes. If you want to remove solid stains, you'll need to use Thompson's® WaterSeal® Maximum Strength Deck Stripper.
The 3-4-5 rule is a fundamental geometry technique (based on the Pythagorean theorem) used to ensure your deck frame forms a perfectly square 90∘90 raised to the composed with power90∘ corner. It works by making the side lengths of a triangle proportional to the numbers 333, 444, and 555.
Winter is usually not recommended, as cold weather can prevent the stain from penetrating the wood and curing properly. By planning your project for late spring or early fall, you'll have the best chance for success and a beautiful, long-lasting deck finish.
Yes, Dawn dish soap is highly effective and safe for washing decks, including both traditional wood and composite materials. It is excellent at cutting through grease, dirt, and grime.
Use Thompson's WaterSeal Heavy Duty Deck Cleaner with a pump-up sprayer for an even application. Then, grab a stiff-bristle brush to work the cleaner deep into the wood. Wait 10 to 15 minutes and rinse it off.
Yes, rain on freshly sealed concrete can cause problems like bubbling, white spots, or a cloudy finish. If it rains before your sealer dries—usually within 24 to 48 hours—the water can get trapped under the surface and ruin the protective coating.
Yes, you can seal a deck without staining it. You can achieve this using a clear wood sealer, which penetrates the wood or sits on top to repel moisture, preventing rotting and warping while keeping the wood's natural color.
Due to the weather cycles, pressure treated wood is susceptible to splits, cracks, checks and other appearance issues. To minimize these concerns, it's important to stain or seal your project as soon as possible after completion.
The most common chemical used to treat lumber used to be chromated copper arsenate, or CCA. In 2003, however, the Environmental Protection Agency restricted the use of CCA in residential settings due to health and environmental concerns about arsenic leaching out of the wood.
Motor oil repels water and deters insects, effectively slowing down rot in outdoor wood, such as fence posts or barns. However, it is an unregulated, environmentally hazardous practice. It never fully dries, leaches into the soil, emits a strong odor, and poses toxicity risks.